1. Field of the Invention
The present invention relates to a copier, facsimile apparatus, printer, plotter, stencil printer or similar printer, multifunction machine or similar image forming apparatus and more particularly to a document reading device mounted on such an image forming apparatus, a document reading device including a scanner or similar image reading unit and a cover plate mounted on the document reading device.
2. Description of the Background Art
It is a common practice with a document reading device mounted on an image forming apparatus or an image reading device including a scanner or similar image reading unit to include a cover plate configured to press a document against a glass platen or similar document table or to provide an ADF (Automatic Document Feeder) with such a cover plate. This kind of document reading device is taught in, e.g., Japanese patent laid-open publication Nos. 8-195852, 8-234330, 9-244161 and 6-222479 and Japanese Patent No. 2652021.
Japanese patent laid-open publication No. 8-195852, for example, teaches a cover plate configured separately from an ADF structural body which is heavy.
A scanner or similar image reading device or a document reading device has customarily been required to selectively use light or white background or dark or black background when processing an input image. However, it is necessary for a user needing black background to prepare a black background member beforehand and substitute it for a white or usual background member, limiting serviceability or operability available with the document reading device.